This invention relates generally to a mobile surface scrubber for scrubbing a surface wetted with cleaning solution, and more particularly to a high efficiency squeegee system for collecting liquid on the wetted surface.
Mobile surface scrubbers typically include a system for dispensing cleaning solution on the surface to be cleaned, scrub brushes for scrubbing the wetted surface and one or more squeegees for collecting used solution on the surface. A vacuum system is usually connected to the squeegee for removing the cleaning solution from the surface once collected. In addition, scrubbers frequently include sweeper brushes to sweep loose debris from the surface into an on-board recovery bin before the surface is wetted. The scrubbers may be used to concurrently sweep, scrub and squeegee the surface, or they may be used to perform only one or two of these functions at a time.
Conventional scrubber squeegees are arcuate so they direct liquid toward their center as they move across the surface. In order to improve the removal of liquid, conventional scrubber squeegees have two blades mounted in spaced apart relation so they form a curved chamber between them. As the scrubber moves across the surface, liquid passes under the leading blade and accumulates in the chamber. A vacuum system communicates with the chamber through a port located above the center of the chamber to draw the accumulated liquid into a holding tank and remove it from the surface.
One or more openings are provided in or beneath the leading squeegee blade to permit liquid to flow into the chamber between the blades. For instance, sometimes the leading blade is mounted so its lower edge is spaced above the surface to permit liquid to pass beneath the blade. In other instances, the leading blade has either slits or slots extending through it. Usually these openings extend up from the lower edge of the blade at intervals along the blade. Each opening has parallel sides spaced by a gap to permit liquid to flow past the blade as it wipes the surface. The gaps provided by the slits are narrow and thus do not allow an appreciable amount of liquid to flow into the chamber. The slots provide wider gaps and permit more liquid to flow past the leading blade into the chamber. However, the wider slots also allow a relatively large amount of ambient air to pass into the chamber. As larger amounts of air are allowed into the chamber, the flow rate required to be produced by the vacuum system to draw liquid out of the chamber increases. Further, the power requirements of the motor used in the vacuum system increase as the flow rate requirements increase.